In recent years, an image processing system for providing a plurality of input means for an image processing device has become widespread. For example, there is a system for providing an external extension panel in addition to an operation panel built in an image processing device, and for providing a device setting tool operating on a host PC. Further, in Patent Document 1, in order to prevent malfunction due to simultaneous operations of an image processing device through a plurality of input means, an image processing system capable of setting the priority of operation instructions from the plurality of input means is disclosed.